Insertion guide

Abstract

A device for insertion of a flexible needle or other such instrument into a tissue, incorporating a collapsible support guide which supports that part of the needle which has not yet penetrated the tissue, preventing it from buckling, and an arrangement which pulls the needle from its proximal end to provide sufficient force for the penetration process. The collapsible support guide can be a pair of flexible strips connected along their length and enclosing the needle along its uninserted length in order to support it, with a mechanism at the distal end of the device to peel the strips from the needle as it is inserted. Insertion can be achieved by a pair of rollers engaging and advancing the strips distally. Alternatively, a telescopic support tube can be used to support the needle, the tube collapsing telescopically as the needle is inserted, to maintain clearance above the needle.

The invention claimed is: 
     
       1. An insertion device for insertion of a medical tool towards a target in a body of a subject, the insertion device comprising:
 two flexible strips connected to each other along at least a portion of their lengths and having a central channel therebetween configured to receive the medical tool; and 
 two rollers disposed on opposite sides of the connected two flexible strips; 
 wherein the connected two flexible strips and the medical tool are configured to be secured together at an end remote from the two rollers, upon the medical tool being received within the central channel, such that counter-rotation of the two rollers, in an appropriate direction, moves the connected two flexible strips towards the two rollers, resulting in advancement of the medical tool towards the target; and 
 wherein the insertion device comprises two separate units configured to be connected to and disconnected from each other, each unit comprising one flexible strip of the two flexible strips and one roller of the two rollers. 
 
     
     
       2. An insertion device according to  claim 1 , wherein each roller of the two rollers comprises a plurality of protrusions arranged along its circumference, the plurality of protrusions being configured to engage with corresponding plurality of holes formed along the length of each flexible strip of the two flexible strips. 
     
     
       3. An insertion device according to  claim 2 , wherein the distance between two adjacent protrusions of the plurality of protrusions is larger than the distance between two adjacent holes of the plurality of holes. 
     
     
       4. An insertion device according to  claim 1 , wherein the two flexible strips are connected to each other on at least one side of the central channel, and are not connected to each other in a region of the central channel. 
     
     
       5. An insertion device according to  claim 1 , further comprising a holder member configured to secure together the connected two flexible strips and the medical tool at the end remote from the two rollers. 
     
     
       6. An insertion device according to  claim 1 , further comprising a guide member comprising:
 one or more cavities configured to accommodate the two rollers; and 
 an opening configured to allow passage of the medical tool therethrough. 
 
     
     
       7. An insertion device according to  claim 6 , wherein the opening comprises a constraining mechanism configured to be adjusted according to the dimensions of the medical tool, at least a portion of the constraining mechanism being disposed within the opening, wherein the constraining mechanism comprises at least two portions disposed opposite each other, and wherein at least one of the at least two portions is adapted to be moved towards another of the at least two portions. 
     
     
       8. An insertion device according to  claim 1 , further comprising a separating feature configured to direct each flexible strip of the two flexible strips around a roller of the two rollers, wherein the separating feature comprises at least one of:
 (a) unconnected distal ends of the two flexible strips, each of the unconnected distal ends being wound around an associated roller of the two rollers, and 
 (b) two structural edges, each flexible strip of the two flexible strips being directed by a structural edge of the two structural edges around an associated roller of the two rollers. 
 
     
     
       9. An insertion device according to  claim 1 , wherein the central channel includes weakened sections along its length to facilitate winding of each flexible strip of the two flexibles strip around a roller of the two rollers. 
     
     
       10. An insertion device according to  claim 1 , wherein the medical tool comprises a tip, and the insertion device further comprises a protecting element configured to prevent the tip from contacting an internal surface of the central channel as the medical tool is advanced in the direction of the target. 
     
     
       11. An insertion device according to  claim 1 , further comprising an encoder configured to determine the position of the medical tool. 
     
     
       12. An insertion device according to  claim 1 , wherein the medical tool comprises one or more of: a needle, a cannula, a catheter, an introducer, a port, a fluid delivery tube or an electrode rod. 
     
     
       13. An insertion device according to  claim 1 , wherein each roller of the two rollers comprises two rollers assembled on a single shaft. 
     
     
       14. An insertion system for insertion of a medical tool towards a target in a body of a subject, the insertion system comprising:
 an insertion device comprising:
 two flexible strips connected to each other along at least a portion of their lengths and having a central channel therebetween configured to receive the medical tool; and 
 two rollers disposed on opposite sides of the connected two flexible strips; 
 wherein the connected two flexible strips and the medical tool are configured to be secured together at an end remote from the two rollers, upon the medical tool being received within the central channel, such that counter-rotation of the two rollers, in an appropriate direction, moves the connected two flexible strips towards the two rollers, resulting in advancement of the medical tool towards an insertion target; 
 
 a housing configured to receive the insertion device; 
 a locking mechanism configured to lock the insertion device within the housing; and 
 an actuation mechanism configured to counter-rotate the two rollers, the actuation mechanism comprising at least one motor and at least one gear. 
 
     
     
       15. An insertion system according to  claim 14 , wherein a first portion of the actuation mechanism is coupled to the housing, and a second portion of the actuation mechanism is coupled to a guide member of the insertion device. 
     
     
       16. An insertion system according to  claim 14 , wherein the locking mechanism comprises:
 a rotating member coupled to the insertion device; and 
 one or more slits formed in the housing; 
 wherein rotation of the rotating member such that at least a portion of the rotating member enters at least one of the one or more slits locks the insertion device within the housing. 
 
     
     
       17. An insertion system according  claim 14 , further comprising:
 a front leading element coupled to the insertion device; and 
 a back leading element coupled to the housing; 
 wherein the front and back leading elements are configured to receive therebetween an unconnected end of a flexible strip of the two flexible strips after the unconnected end is wound around a roller of the two rollers. 
 
     
     
       18. An insertion system according to  claim 14 , wherein each roller of the two rollers comprises a plurality of protrusions arranged along its circumference, the plurality of protrusions being configured to engage with corresponding plurality of holes formed along the length of each flexible strip of the two flexible strips. 
     
     
       19. An insertion system according to  claim 14 , wherein the medical tool comprises one or more of: a needle, a cannula, a catheter, an introducer, a port, a fluid delivery tube or an electrode rod. 
     
     
       20. An insertion device for insertion of a medical tool towards a target in a body of a subject, the insertion device comprising:
 two flexible strips connected to each other along at least a portion of their lengths and having a central channel therebetween configured to receive the medical tool; 
 two rollers disposed on opposite sides of the connected two flexible strips; 
 a guide member comprising:
 one or more cavities configured to accommodate the two rollers; 
 an opening configured to allow passage of the medical tool therethrough; and 
 a constraining mechanism configured to be adjusted according to the dimensions of the medical tool, the constraining mechanism being at least partially disposed within the opening, 
 
 wherein the connected two flexible strips and the medical tool are configured to be secured together at an end remote from the two rollers, upon the medical tool being received within the central channel, such that counter-rotation of the two rollers, in an appropriate direction, moves the connected two flexible strips towards the two rollers, resulting in advancement of the medical tool towards the target.